A medical image diagnosis apparatus receives signals from a test body and derives the organization information thereof. Some medical image diagnosis apparatuses have a body as well as a device operating in cooperation with this. Exemplary medical image diagnosis apparatuses include an X-ray diagnosis apparatus, an MRI (Magnetic Resonance Imaging) apparatus, an ultrasound diagnosis apparatus, etc. As an example of the present device of the X-ray diagnosis apparatus, a wireless X-ray detector (wireless FPD (Flat Panel Detector)) is cited. As an example of the present device of the MRI apparatus, an RF coil unit is cited. As an example of the present device of the ultrasound diagnosis apparatus, an ultrasound probe is cited.
These devices operate with an electric power supply from the outside. A battery is mounted on the device wirelessly connected to the body. As a charging method of a battery, a non-contact charging method is known which uses electromagnetic induction from a mere coil.